Method of severing a continuous tube into can bodies



1961 P. GOTSCH ET Al. 2,997,904

METHOD OF SEVERING A CONTINUOUS TUBE INTO CAN BODIES Filed Nov. 14, 1956 S Sheets-Sheet 1 FIG.3

[N VENTOBS LENAFlD P. GOTSCH HAROLD R. VITENSE FREDERICK C. BASELT aka/A? /FGMM.

FIG.I

ATTORNEYS Aug. 29, 1961 P. GOTSCH ETAI.

METHOD OF SEVERING A CONTINUOUS TUBE INTO CAN BODIES Filed NOV. 14, 1956 3 Sheets-Sheet 2 T E 5 M m S Mm BE N m m N b WT WPR WHQ M N Dm l RLR M M E u HF Y B Aug. 29, 1961 P. GOTSCH ET AL 2,997,904

METHOD OF SEVERING A CONTINUOUS TUBE INTO CAN BODIES Filed Nov. 14, 1956 3 Sheets-Sheet 5 2,997,904- METHOD OF SEVERING A CONTINUOUS TUBE INTO CAN BODIES Lenard P. Gotsch, Barrington, and Harold R. Vitense, Mundelein, 111., and Frederick C. Baselt, New York, N.Y., assignors to American Can Company, New York, N.Y., a corporation of New Jersey v Filed Nov. 14, 1956, Ser. No. 622,163 7 Claims. (Cl. 8337) The present invention pertains to a method for separating a continuous tube into predetermined lengths. More particularly, it pertains to a method for separating a continuous, light gauge metal tube, which is already separated around the major portion of its circumference, into individual can bodies by severing the remaining portion of the tube.

The present invention is applicable to the separation into predetermined lengths of a partially slit tube of any flexible material such as plastic, paper or other fibrous material, or metal even up to a relatively heavy gauge. However, for the purpose of this disclosure and explanation, the specification set forth hereinafter will describe the invention in relation to the formation of tubular, light gauge, metal can bodies. The cross-sectional configuration denoted by the terms tube and tubular as used herein is meant to include polygonal, e.g. square, rectangle, hexagonal, etc., as well as circular.

The can making industry has long recognized the advantages of making can bodies from sheet steel in coil form. In this method of manufacture the steel is continuously fed from the coil into a tube forming machine wherein the marginal edges of the sheet are joined such as by welding, soldering, etc., and thereafter the resulting continuous tube is separated into individual can bodies. This general method has been practiced for many years in the manufacture of relatively thick walled metal tubes. However, this general method has previously never been commercially feasible in the making of metal can bodies because the relatively light gauge of steel used, i.e. about 0.008-0.0l2 inch, made the separation of the tube into individual bodies too slow and inaccurate.

A number of methods for bringing about this separation of a continuous tube into individual can bodies is suggested by the prior art, for example United States Patents 2,177,104; 2,444,463; 2,444,465; and 2,484,854. However, none of these prior art methods are sufliciently accurate or rapid to be commercially satisfactory.

It is therefore an object of the present invention to provide a method for rapidly and accurately separating a continuous tube composed of any flexible material into predetermined lengths.

Another object is to provide a method for separating a continuous, thin-walled, metal tube into individual can bodies rapidly and accurately.

A further object is to provide a method of the class described wherein no undesired burrs or slivers remain on the individual separated lengths.

Yet another object is to provide a method of the class described which may be operated continuously and without the necessity of halting the movement of the tube each time a predetermined length is separated therefrom.

Another object is the provision of a method of the character described which may be used to provide individual, predetermined lengths having a cross-sectional configuration other than circular, e.g square, polygonal, etc.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

The above and other objects are obtained by providing states Patent icg a continuous tube moving along a straight line path of travel with its marginal edges securely bonded, as by welding, soldering, etc., to form a longitudinally extending side seam, and the wall of which tube, at predetermined intervals along its length, is completely cut through circumferentially except for a small portion including the bonded side seam, changing the path of travel of the leading end of the tube to open a V-shaped space between adjacent, predetermined lengths of tube, inserting a .severing means, such as a knife, saw, punch, etc., into the V-shaped space, and severing the remaining uncut portion, i.e. at the bonded side seam, of the tube.

Referring to the drawings:

FIGURES l and 2 are continuing perspective views of one form of apparatus for carrying out the steps of slitting partially transversely the flat strip stock as it comes off a coil thereof and forming this partially slit stock into a continuous tube;

FIG. 3 is an enlarged plan view of a portion of the partially transversely slit flat strip showing the position of the slits;

FIG. 4 is a side elevational view of one form of apparatus for carrying out the steps of the present invention comprising separating an individual can body from a partially slit, continuous tube;

FIG. 5 is an elevational View along the side seam of a fragment of the tube immediately after severance but before separation of a can body from the tube and showing the configuration of the severance; and

FIG. 6 is an elevational view along the side seam of a fragment of a can body after separation thereof from the tube showing the arcuate notch formed when the body is severed from the tube.

FIG. 7 is a slightly enlarged fragmentary sectional view taken along the line 7-7 in FIG. 4.

As a preferred or exemplary embodiment the drawings illustrate one form of apparatus for carrying out the method of the present invention. A strip 10 of sheet metal, such as tin plate, black plate or the like, is supplied from a coil 11 of the material. The strip 10 is of a width approximately equal to the circumference of the can bodies to be produced and of a length sufiicient to provide a considerable number of can bodies. The unwinding of strip 10 from coil 11 and the feeding of the strip for subsequent operations is performed by a pair of feed rollers 12 which friotionally engage the upper and lower surfaces of the strip disposed between the rollers. After passing between the rollers 12, the strip 11 passes between a pair of opposed rollers 13, the upper one of which carries one or more transversely extending knives 14 and the lower one has cooperating recesses (not show) for the purpose of slitting the strip 10 transversely a portion of its width. The rotation of the knives 14 as the strip 10 passes between the rollers 13 produces a series of slits 15 at spaced intervals along the length of the strip in accordance with the length of the can bodies to be produced. As best shown in FIG. 3, the slits 15 extend across the central portion of the strip 10 but terminate just short of the marginal or side edges of the strip.

The partially slit strip 10 then passes between a series of forming rollers 16 and around a mandrel 17 (FIG. 2) whereby the strip is gradually brought into tubular shape with the unslit marginal edges overlapped. These overlapped marginal edges are then securely bonded to one another such as by passing them under a rotating resistance welding electrode 18 to form a continuous tube 19. Although the tube 19 is partially divided into potential can bodies or cylinders 20 by virtue of the spaced slits 15, it remains an integral, unitary structure by virtue of the unslit portion 21 including the bonded side seam 22. The tube 19 is then fed along a straight line path of travel (FIG. 4) between a pair of opposed guide rollers 23 (only one shown) whereby the spaced slits 15 remain unslit portion 21. One such other method is that shown in United States Patent 2,187,740 issued to John Ml Hothersall on January 23, 1940 wherein the tube is composed of a series of cylinders formed from individual fiat blanks'and integrally connected along their bonded side seams.

To open and maintain opened, V-shaped spaces' 24, the forward or leading end of the tube 19 is picked-up and preferably carried around a circular path by and on the peripheral surface of a rotating wheel 25. The wheel 25 is fixed on a rotating shaft 26 driven by any suitable means (not shown). As shown in FIG. 4, the outline of the wheel 25 is not actually circular but is a regular polygon, the peripheral surface of which is composed of a series of flats 27 each equal to the length of one cylinder 20. The purpose of the flats 27 are to provide close engagement between the periphery of the wheel and whole length of the side seam 22 in contact with the wheel 25 and support for the portion of the tube 19 on the wheel. The connected cylinders 20 constituting the portion of the tube 19 on the wheel 25 may be held in place on the wheel by any suitable means such as by permanent magnets set into the periphery of the wheel. It is to be understood that the path of travel of the forward end of the tube 19 need not be circular; but may be any arcuate path, for example eliptical.

When the foremost cylinder 20 reaches some predetermined position on the wheel 25, such as the top of wheel as shown in FIG. 4, a cutting element 28, actuated by a. suitable mechanism not shown, enters the space 24 and severs the unslit portion 21 thereby completely detaching a can body 29 from the tube 19. The apex 36 between adjacent flats 27 on the periphery of wheel 25 forms a support or anvil against which the unslit portion 21 is severed by the cutting element 28. This cutting element may be of any desired type such as a saw, punch, knife, etc. It will be understood that the complementary surface of the wheel 25 against which the cutting element operates has the necessary configuration for cooperation with the cutting element. For example, if a saw is used, the complementary surface of the wheel will be grooved; and if element 28 is a punch, the wheel surface will provide a matching die. This latter mentioned punch and die meth d of severing the unslit portion 21 is preferred in the instant invention.

The cutting element or punch 28 and its cooperating die (not shown) are so designed that a sliver of metal is removed from the side seam of the cylinder 20 being separated and from the adjacent end of the tube 19.

This method of severing the unslit portion 21 results in the formation of an arcuate or serni-eliptical notch 31 (FIGS. 5 and 6) in each end of the side seam of the can body 29. By this means the necessity is obviated for extremely accurate positioning of the line of severance between adjacent cylinders to avoid a burr or undesirably long side seam on one can body. This lessening of the degree of accuracy required in severing the can body from the tube permits greater speed in performing the operation. Unexpectedly and collateral to the instant invention, it was found that better and more easily formed end seams resulted from can bodies having the notch 31 at the ends of their side seams.

After severance of the unslit portion 21, the can body 29 is completely separated from the tube 19 and is fed into a chute or conveyor 32 for transfer 'to a point of subsequent operation.

The instant invention may be used for severing and separating can bodies from a continuous tube that is advanced intermittently. That is, the forward or lineal 'motion of the tube is halted during the severing operation. On the other hand, by coordinating the speeds and tim ing of the various elements involved in the severing operation, the method of the present invention is well suited for separating can bodies from a non-stopping or continually moving continuous tube. The method Whereby the movement of the tube is non-intermittent or continual is preferred.

Severing an individual length or can body 29 from a continually moving tube may be accomplished by having the cutting element 28 move with the foremost cylinder 20 to be severed during the insertion of the cutting element 28 into the foremost space 24-, the actual severing of the foremost portion 21 and the withdrawal of the element 28. Thereafter, the cutting element 28 will move in a direction opposite that of the next succeeding cylinder 20 to a position above the newly presented, foremost space 24 and the operation is then repeated. Severing lengths from a continuously moving tube could be performed by other methods and by suitable automatic machinery such as that disclosed in patent application Serial No. 676, 073 filed August 5, 1957, owned by the assignee of the instant invention.

FIG. 4 shows a plurality of cutters 28 adapted to sever lengths 20 from the continuous tube without interrupting their forward movement. The cutters are disposed at each apex 30 around the periphery of the wheel 25, each mounted thereon for oscillation to and from a die 34 on the periphery of the wheel, as shown in FIG. 7. The upper end of each cutter is secured to the free end of a long arm 3-5 of a bell crank 36 that is pivotally mounted at 37 to the wheel 25. A link 38 is pivotally connected at one end 3 9 to the short arm of the bell crank and is likewise connected at its opposite end 40 to a slide 41 mounted for radial reciprocation at 42 in the wheel 25. A follower roller 43, mounted for free rotation at the inner end of each slide, engages the Walls of a cam groove 44 in a stationary cam 45, so that, upon counterclockwise rotation of the wheel 25, as viewed in FIG. 4, the roller 43 of each slide follows, for over an inner portion of the groove that is concentric with the wheel 25, to retain the cutter element in its retracted position shown in FIG. 7. However, as the roller follows a rise 46 in the cam groove, the slide 41 is moved radially outwardly and transmits its motion, through link 38, to the lever 36, causing the latter to oscillate about its pivot 37 and rock the cutter 28 inwardly toward the unslit portion 21 between the cylinders 20. When the roller reaches the peak 47 of the rise 46, the cutter will have cooperated with the die 34 to sever a length 20 from the continuous tube. Thereafter, the follower roller is moved radially inwardly by its coaction with cam 45 causing withdrawal of the cutter element 28 to its retracted position until its next cutting operation.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the steps of the method described and their order of accomplishment without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the method hereinbefore described being merely a preferred embodiment thereof.

We claim:

1. A method of separating into predetermined lengths a continuous tube of flexible material, which tube is transversely slit around the greater portion of its circumference at spaced intervals corresponding to said predetermined lengths but is integral and unslit along a longitudinally extending portion thereof, comprising moving said tube along a straight line path of travel whereby said transverse slits remain closed, passing the forward end of said tube onto an arcuately moving supporting surface with substantially the entire length of the unslit portion of said forward end in contact with said surface, moving said forward end in an arcuate path with said surface while maintaining said contact of said unslit portion with said arcuately moving supporting surface to change the direction of said forward end from straight line travel to an arcuate path of travel whereby a V-shaped space is opened and maintained open during the arcuate travel of said tube between successive predetermined lengths, providing a cutter element spaced outwardly from said supporting surface, moving said cutter element along said arcuate path in timed relation With said supporting surface and into the foremost of said spaces and against the unslit portion at the apex of said foremost space to position said unslit apex for severance between and contiguous said element and said surface, continuing said movement of said element inwardly and arcuately to sever said unslit apex, and separating the completely severed length from said tube.

2. A method of continuously separating into predetermined lengths a thin walled metal tube having a longitudinally extending bonded side seam, said tube having transverse slits extending substantially from one side of said side seam circumferentially around said tube to the other side of said side seam but being continuous and unslit along the side seam portion of said tube, said slits being located at spaced intervals along said tube corresponding to said predetermined lengths, comprising continuously moving said tube along a straight line path of travel whereby said predetermined lengths are kept in peripheral abutment and said slits remain closed, passing the forward end of said tube onto an arcuately moving supporting surface with substantially the entire length of the unslit side seam portion of said forward end in contact with said surface, moving said forward end in an arcuate path 'with said surface while maintaining said contact of said unslit side seam portion with said arcuately supporting surface to change the direction of said forward end from straight line travel to an arcuate path of travel whereby a V-shaped space is opened and maintained open during the arcuate travel of said tube between successive predetermined lengths, providing a punch element spaced outwardly from said supporting surface, moving said punch element along said arcuate path in timed relation with said supporting surface and into the fore most of said spaces and against the unslit portion at the apex of said foremost space to position said unslit apex for severance between and contiguous said element and said surface, continuing said movement of said element through said unslit apex and into a cooperating recess in said surface to punch out a sliver of the remaining metal connecting said length to said tube at said apex to sever said length from said tube and to form a notch in the side seam portion of the peripheries of both the severed predetermined length and the adjacent tube end, and sepa rating the thus severed length from said tube.

3. The method set forth in claim 1 wherein the flexible material of said tube is sheet metal.

4. The method set forth in claim 1 wherein said arcuate path of travel is circular.

5. The method set forth in claim 1 wherein said length is severed by punching out a section of material between the terminal ends of said circumferential slit to form a. notch in the periphery of the severed length and in the periphery of the tube from which said length is severed.

6. The method set forth in claim 5 wherein said notch is arcuate in shape.

7. The method set forth in claim 1 wherein the movement of said tube along its paths of travel is continuous.

References Cited in the file of this patent UNITED STATES PATENTS 955,113 Bilgram Apr. 12, 1910 1,710,395 Williams Apr. 23, 1929 1,967,212 Avery July 24, 1934 2,187,740 Hothersall Jan. 23, 1940 2,339,072 Herzog et a1 Ian. 11, 1944 2,444,465 Peters July 6, 1948 2,586,903 Badenhausen et a1 Feb. 26, 1952 2,711,792 McFall June 28, 1955 

